//==============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 3.0 of the License, or
//  any later version.
//
//  The GPSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//  
//  This software was developed by Applied Research Laboratories at the
//  University of Texas at Austin.
//  Copyright 2004-2020, The Board of Regents of The University of Texas System
//
//==============================================================================

//==============================================================================
//
//  This software was developed by Applied Research Laboratories at the
//  University of Texas at Austin, under contract to an agency or agencies
//  within the U.S. Department of Defense. The U.S. Government retains all
//  rights to use, duplicate, distribute, disclose, or release this software.
//
//  Pursuant to DoD Directive 523024 
//
//  DISTRIBUTION STATEMENT A: This software has been approved for public 
//                            release, distribution is unlimited.
//
//==============================================================================

/**
 * @file RinexNavFilterOperators.hpp
 * Operators for FileFilter using Rinex navigation data
 */

#ifndef GPSTK_RINEXNAVFILTEROPERATORS_HPP
#define GPSTK_RINEXNAVFILTEROPERATORS_HPP

#include "GPSWeekSecond.hpp"

#include "FileFilter.hpp"
#include "RinexNavData.hpp"
#include "RinexNavHeader.hpp"
#include "GPSWeekSecond.hpp"

#include <set>

namespace gpstk
{
      /// @ingroup FileHandling
      //@{

      /// This compares all elements of the RinexNavData with less than.
   struct RinexNavDataOperatorLessThanFull : 
      public std::binary_function<gpstk::RinexNavData, 
                                  gpstk::RinexNavData, bool>
   {
   public:
      bool operator()(const gpstk::RinexNavData& l,
                      const gpstk::RinexNavData& r) const
      {
         if (l.getXmitTime() < r.getXmitTime())
            return true;
         else if (l.getXmitTime() == r.getXmitTime())
         {
               // compare the times and all data members
            if (l.time < r.time)
               return true;
            else if (l.time == r.time)
            {
               std::list<double>
                  llist = l.toList(),
                  rlist = r.toList();
                  
               std::list<double>::iterator 
                  litr = llist.begin(), 
                  ritr = rlist.begin();
                  
               while (litr != llist.end())
               {
                  if (*litr < *ritr)
                     return true;
                  else if (*litr > *ritr)
                     return false;
                  else
                  {
                     litr++;
                     ritr++;
                  }
               }
            }
         } // if (lXmitTime == rXmitTime)

         return false;
      }
   };

      /// This compares all elements of the RinexNavData with equals
   struct RinexNavDataOperatorEqualsFull : 
      public std::binary_function<gpstk::RinexNavData, 
                                  gpstk::RinexNavData, bool>
   {
   public:
      bool operator()(const gpstk::RinexNavData& l,
                      const gpstk::RinexNavData& r) const
      {
            // compare the times and all data members
         if (l.time != r.time)
            return false;
         else // if (l.time == r.time)
         {
            std::list<double>
               llist = l.toList(),
               rlist = r.toList();

            std::list<double>::iterator 
               litr = llist.begin(), 
               ritr = rlist.begin();

            while (litr != llist.end())
            {
               if (*litr != *ritr)
                  return false;
               litr++;
               ritr++;
            }
         }

         return true;
      }
   };

      /// Only compares time.  Suitable for sorting a RinexNav file.
   struct RinexNavDataOperatorLessThanSimple : 
      public std::binary_function<gpstk::RinexNavData, 
                                  gpstk::RinexNavData, bool>
   {
   public:
      bool operator()(const gpstk::RinexNavData& l,
                      const gpstk::RinexNavData& r) const
      {
         if (l.getXmitTime() < r.getXmitTime())
            return true;
         return false;
      }
   };

      /// Combines RinexNavHeaders into a single header, combining comments
      /// This assumes that
      /// all the headers come from the same station for setting the other
      /// header fields. After running touch() on a list of RinexNavHeader,
      /// the internal theHeader will be the merged header data for
      /// those files.
   struct RinexNavHeaderTouchHeaderMerge :
      public std::unary_function<gpstk::RinexNavHeader, bool>
   {
   public:
      RinexNavHeaderTouchHeaderMerge()
            : firstHeader(true)
      {}

      bool operator()(const gpstk::RinexNavHeader& l)
      {
         if (firstHeader)
         {
            theHeader = l;
            firstHeader = false;
         }
         else
         {
            std::set<std::string> commentSet;

               // insert the comments to the set
               // and let the set take care of uniqueness
            copy(theHeader.commentList.begin(),
                 theHeader.commentList.end(),
                 inserter(commentSet, commentSet.begin()));
            copy(l.commentList.begin(),
                 l.commentList.end(),
                 inserter(commentSet, commentSet.begin()));
               // then copy the comments back into theHeader
            theHeader.commentList.clear();
            copy(commentSet.begin(), commentSet.end(),
                 inserter(theHeader.commentList,
                          theHeader.commentList.begin()));
         }
         return true;
      }

      bool firstHeader;
      gpstk::RinexNavHeader theHeader;
   };

      /// Filter based on PRN ID.
   struct RinexNavDataFilterPRN : 
      public std::unary_function<gpstk::RinexNavData,  bool>
   {
   public:
      RinexNavDataFilterPRN(const std::list<long>& lst )
            :prnList(lst)
      {}
         /// This should return true when the data are to be erased
      bool operator()(const gpstk::RinexNavData& l) const
      {
         long testValue = (long) l.PRNID;
         return find(prnList.begin(), prnList.end(), testValue )
            == prnList.end(); 
      }
   private:
      std::list<long> prnList;
   };

      //@}

}


#endif
